International Journal of Chemical Studies 2017; 5(6): 618-621 P-ISSN: 2349–8528 E-ISSN: 2321–4902 IJCS 2017; 5(6): 618-621 Chemical ecology and pest management: A review © 2017 IJCS Received: 11-09-2017 Accepted: 17-10-2017 Tamoghna Saha and Nithya Chandran Tamoghna Saha Abstract Department of Entomology, The origin of chemical ecology started from its first identification of an insect sex pheromone nearly fifty Bihar Agricultural University, Sabour, Bhagalpur, Bihar, India years ago. From commercial point of view, the most valuable contribution of chemical ecology remains the insect sex pheromones and their role in pest management. However, the progress of integrated pest Nithya Chandran management (IPM) strategies is escalating since many problems appeared with the use of synthetic Division of Entomology, Indian pesticides. Semiochemicals are informative molecules used in insect-insect or plant-insect interactions Agricultural Research Institute, are more and more considered within IPM strategies as alternative or complementary approach to New Delhi, India insecticide treatments. In fact, these species-specific compounds do not have any adversely affectation of beneficial organisms and do not generate any threat to resistance against insect pest as detected with insecticides. Since their complex biological activity, their dispersion in the environment to be protected or monitored needs the elaboration of slow-release mechanisms certifying a controlled release of the biologically active volatile composites. Hence, the IPM strategy of applying all the available control measures with thoughtful intent to protect the significance of each will be necessary. Semiochemicals, and particularly insect sex pheromones, are very useful part of detection, monitoring, and control programs for agricultural crops. Keywords: Semiochemicals, sex pheromone, alarm pheromone, oviposition-deterring pheromone, allomone, kairomone Introduction The term "semiochemical" derived from the Greek word "semeon," which means "sign" or "signal" and it is used since 1971. Depending on the function of a semiochemical, this group of chemicals can be further divided into two classes: pheromones, and allelochemicals. From its beginning as a field, chemical ecology has always had a strong interdisciplinary flavour. Both major groups of chemicals are further subdivided on the basis of their function. Allelochemicals can be divided in to signals that benefits that benefit the receiver [18] (kairomones), the emitter (allomones), or both (synomones) (Norduland et al., 1981) . In pheromone, sex pheromones, for example, are chemicals which mediate interactions between the sexes of the same species; mainly produced by females and to attract males, whereas some examples of male-produced pheromones are also known. Other types of pheromones include alarm pheromones (which aware other members of the same species to the presence of menace), trail pheromones (which guide social insects to distant food sources), aggregation pheromones (which attract individuals of both sexes), oviposition- deterring pheromones (which discourage females from laying eggs in the same resource as another female), and so on. Pheromones may bring out an immediate behavioural response (‘releaser’ pheromones), or may mediate more long-term, physiological changes (‘primer’ pheromones). Mainly sex pheromones are not a single compound, but rather a blend of several compounds which must be present in the proper concentration and ratio to obtain the proper behavioural response (Norduland et al., 1981) [18]. All types of semiochemicals may be biologically active at very low concentrations, a fact that has often made their isolation and identification technically challenging. The first semiochemical to be chemically characterized was the sex pheromone of the silkworm moth (Bombyx mori) in 1959. There is an environmental concern and public demand for decline in the use of toxic insecticides for pest control. Semiochemicals have enormous potential to give substitute Correspondence results, because they are moderately non toxic to vertebrates and to beneficial insects, are Tamoghna Saha generally used in small amounts, and are often species specific. Department of Entomology, Bihar Agricultural University, Sabour, Bhagalpur, Bihar, India ~ 618 ~ International Journal of Chemical Studies Semiochemicals and their potential in insect pest and it is species specific semiochemical baited monitoring management traps, with the aim of suppressing or eradicating populations Right now the most intensively used semiochemicals in insect of target pests by capturing as many as individuals as pest management are the sex pheromones, mostly those of possible. To accomplish this, traps have to confine a large lepidopteran insects, which were among the first to be proportion of the pest population in an area, before mating recognized and synthesized. Regarding pest management is and oviposition, and retain or kill captured individuals. The concerned, pheromones have the significant attributes to lure which will be used for mass trapping must be more species specificity-approximately, potency and low toxicity. efficient than natural sources of attraction such as food or The semiochemicals are not, however, direct alternatives for mates / oviposition sites and perfectly maintain the chemical insecticides, being used not as ‘killing agents’ per effectiveness throughout the whole period of adult insect se, but perform as monitoring tools (to improve the timing of reproductive activity to reduce damage to a minimum. conventional chemical controls). The goals of using Additionally, the yield profits and the cost of traps, and the semiochemicals in pest management are (Reddy et al., 2005) labour involved to install them, must be economically feasible [23] to alternative control methods for this approach to be feasible To monitor pest populations (El-Sayed et al., 2006). In addition to, many cases of the To determine if control is permitted attempted use of mass trapping to manage a range of insect To alter behaviour of the insect pest or its enemies to the pest Lepidoptera, Coleoptera, Homoptera and Diptera and detriment of the pest. classic studies have been itensively reviewed by El-Sayed et al. (2006) and Witzgall et al. (2010) [27]. Advantages of using semiochemicals are Some of the successful examples of mass trapping are banana They have adverse effects only on target pest weevil, fruit fly. The banana weevil, Cosmopolites sordidus, They are relatively non-toxic and required in low was managed by mass trapping using baits prepared from host amounts. plant pseudostems, until the aggregation pheromone was recognized and proved to be more efficient (Alpizar et al., They are non-persistent and environmentally safe. [1] They appear difficult for insects to develop resistant 2012) . Food odours including hydrolysed proteinaceous baits were expanded to catch a broad series of tephritid fruit against. fly species and are still in use in lure (El-Sayed et al., 2009) [9, Right now, about half of the semiochemical-based products 10] are in the form of pheromone traps and lures for monitoring . reasons, whilst the majority of the remainder are for disruption of mating products. Sex pheromone for mating disruption Mating disruption intends to interrupt chemical communication by organism and disrupt normal mating Sex Pheromones for monitoring pest populations activities by dispensing synthetic sex pheromone, thus Witzgall et al. (2010) [27] reported that one of the most widespread and a successful practical application of disturbing the organism’s chance of reproduction (Carde and Minks, 1995) [8]. This can be achieving by using both semiochemicals is in detection and monitoring of pest attractive and non-attractive pheromone mixed together. populations. Semiochemical baited insect monitoring traps Mating disruption can be successful if the large areas are can provide a best solution to solve this problem. The design treated or if the area treated are separated such as in a of the trap will vary according to the target insect, even mountain valley. In recent time, pheromones are used in IPM though numerous standardized designs have been establish to has been reconsidered by Witzgall et al. (2010) [27] and mating work well for a number of different species. The trap develop disruption was reviewed by Rodriguez and Stelinski (2009). in such a way to allow free dispersal of the pheromone, and must incorporate some method of retaining any insects The area under this method has risen almost exponentially from the 1990s, and it is stated that the crop are being attracted by the lure: a glue-covered gummy board, which can controlled for specific pests using mating disruption be eliminated and reinstated as required, is often used. Though the traps are to be economically feasible, the worldwide was 770,000 ha in 2010 (Ioriatti et al., 2011; Witzgall et al., 2010) [12, 27]. There are some reports, from that concentration of pheromone lure must be optimized to carry they reported three species with highest land area under for a period of several weeks, and the pheromone traps must be positioned at the optimum height, density and orientation mating disruption technique were the gypsy moth (Lymantria dispar) in North American forests, the codling moth (Cydia to be most successful. Properly used, pheromone traps can be pomonella) in apple and pear trees worldwide and in EU and more efficient than hand sampling, mainly for detecting pests at